* Renamed Post.find_by_tags into Post.tag_match, made into a full fledged scope

* Post.tag_match no longer takes an options hash (use other arel builders instead)

app/controllers/comments_controller.rb

@@ -30,7 +30,7 @@ class CommentsController < ApplicationController
   
 private
   def index_by_post
-    @posts = Post.find_by_tags(params[:tags]).commented_before(params[:before_date] || Time.now).limit(8)
+    @posts = Post.tag_match(params[:tags]).commented_before(params[:before_date] || Time.now).limit(8)
     respond_with(@posts) do |format|
       format.html {render :action => "index_by_post"}
     end